P.C. Pandey

Availability of the crystallization system in the sugar industry under common-cause failure

Some results from an analytic study of reliability and availability of the crystallizer system in sugar plants are presented. The analytic model was developed in a study of an actual plant. The crystallizer system consists of five basic repairable subsystems in series. Each subsystem is considered as being: good, reduced, or failed. Some subsystems can fail together due to a common cause. The model is based on the Chapman-Kolmogorov equations. Steady-state availability and various state probabilities are derived using Laplace transforms. The usefulness of the study is demonstrated through illustrations. >

Availability of a washing system in the paper industry

Abstract This paper presents the availability and MTTF of a system with three states—good, reduced and failed—consisting of three subsystems in series having one standby unit in subsystem D. Failure and repair rates are taken to be constant. Formulation of the problem is carried out using simple probability considerations. Tables for various parameters are given which are useful to management for predictions about the behaviour of various equipment.

Maintenance planning for pulping system in paper industry

Abstract The paper discusses the pulping system in paper industry consisting of four sybsystems in series. Failure and repair rates in various subsystems are taken to be constant. Formulation of the problem is carried out using simple probability considerations. Tables and graphs for various parameters are given which are useful to management for maintenance planning.

Designing for reliable operation of urea synthesis in the fertilizer industry

Abstract Availability of the urea synthesis process in the fertilizer industry is discussed. The process consists of five subsystems, A , B , D , E l and F m , in series with two standbys in subsystems E and one standby in subsystem F . Subsystem D has two parallel units in operation. Failure and repair rates are taken to be constant. Formulation of the problem is carried out using simple probability considerations. Tables for various parameters are given which are useful to the management for improvement in design and planning for maintenance.

Process design for a crystallization system in the urea fertilizer industry

Abstract The urea crystallization system in the urea fertilizer industry, which consists of five subsystems in series is discussed. The failure rates for all subsystems are constant and the repair rates are arbitrary. A mathematical formulation is carried out using the ‘supplementary variable technique’. The equations are solved by the direct integration method. Expressions for steady-state availability are given followed by a discussion.

Behavioural analysis of a paper production system with different repair policies

Abstract The paper discusses a paper production system in the paper industry with two stages—operating and failed—which consists of four subsystems A , B m , D and E 1 in series, with stand-by units in subsystem E . A special type of failure occurs because of failure of steam supply in the system. Failure and repair rates are taken to be constant. The steady-state behaviour of the system is analysed, and particular cases of scheduled maintenance and preventive maintenance are discussed.

Design and cost analysis of a refining system in the sugar industry

Abstract The role of reliability technology in the sugar industry is discussed. The industry uses various systems, viz. feeding, crushing-cum-filtering, heating-cum-sulphonation and cleaning, cooking, crystallization, separation-cum-cooling and collection for storage. We consider only the refining system, the main functionary part of the sugar industry, which consists of four subsystems A, B, D and E. The failure rate for each subsystem is taken to be constant, whereas the repair rates are variable. The analysis is carried out using a supplementary variable technique. A particular case and a profit-analysis are discussed.

Operational behaviour and profit function for a bleaching and screening system in the paper industry

Abstract This paper discusses the bleaching and screening system (each having four subsystems) in the paper industry with three states: good, reduced and failed. The failure rate for each subsystem is constant while the repair rates are arbitrary. Mathematical formulation is carried out using the supplementary variable technique. The equations are solved using direct integration method. Expressions and graphs for steady state availability and mean time to system failure (MTSF) are given, depicting the effect of failure and repair rates. Profit analysis is also carried out.

Behaviour analysis of a urea decomposition system in the fertilizer industry under general repair policy

Abstract The availability of equipment used for the decomposition process in the urea production system is discussed. The system consists of four subsystems, with a standby unit in one of the subsystems. The failure rate in each subsystem is taken to be constant and the repair rates are general. The problem is formulated using the supplementary variables technique, and the solution is carried out using the direct integration method. Long-run availability of the system is calculated for various cases, and tables are provided for each case.

Cost analysis of a multi-component screening system in the paper industry

Abstract The paper discusses the screening system in the Paper Industry with three states—good, reduced and failed. The failure rates are constant while the repair rates are general. Formulation of the problem is carried out using simple probability consideration. Various probabilities are obtained along with steady state probabilities of the system. Availability and MTTF tables and graphs for various parameters are given which are useful to the designer and the management for improvement in design.